Exemplary embodiments of the invention relate generally to a system and method for sensing current in a conductor. Moreover, such embodiments may relate to sensing current in conductors used in positive train control systems such as wayside control systems.
As part of the US federal legislation (HR2095 Railroad Safety Act), railroads are to implement interoperable Positive Train Control (PTC) by Dec. 31, 2015 on mainlines with passenger/commuter rail traffic and on mainlines which transport Toxic Inhalation Hazard (TIH) materials. To upgrade to interoperable PTC, railroads can implement wayside technologies that enable wireless communications of signal aspect, switch position, and hazard detector status information to the locomotive and/or a central control facility. In some cases, wayside signaling locations may be controlled by relays or other equipment that cannot be easily upgraded to obtain the signal status information via software. In such cases, information such as signal status can be determined by installing sensors on the wires to the signal lamps. Electrical interference or internal failure may cause current or voltage sensors to be susceptible to providing incorrect information. Accordingly, a reliable technique for sensing current in a conductor may be desirable.